This invention relates to a process for separating solid-liquid compositions, as well as to an apparatus for carrying out the process.
A circulating system having a cross-flow type tubular ceramic filter is known. In this system, a liquid, which includes some solids, is contained in a container and is sent into and passes through the tubular ceramic filter. After that, the liquid is sent back into the container. During filtration, the pressure of the liquid is kept at a constant value.
Even if the liquid contains very large solid particles, the residual liquid is successively recirculated. Doubtlessly, such large particles cannot pass through the cross-flow type ceramic filters. But it is difficult to remove such large particles from the liquid before or during filtering.
The liquid is successively recirculated and filtered many times while it contains the large particles. Thus, the liquid is gradually concentrated. When the liquid becomes concentrated, the load applied to the filtering apparatus increases while filtering efficiency decreases. In addition, filters often become clogged.